U.S. Pat. No. 7,362,656 B2 discloses an ultrasonic locating system. This system uses transmission units (sources) for transmitting different encoded ultrasonic pulses. The system further uses a tag (first apparatus) for receiving the different encoded ultrasonic pulses and for transmitting radio signals. These radio signals comprise calculated arrival times for the received ultrasonic pulses and comprise tag identifications. The system also uses a server (second apparatus) for receiving the radio signals and for updating its database. This system is designed for a purpose of determining a location of a tag.